The confirmation of H5 in a fifth farm in Fraser Valley raises additional concerns on the lineage of the H5N2. This issue has not been addressed by Canada, eeven though they have now received samples from at least 4 sources and have determined that the serotype is H5N2.

Canada has never reported high path H5N2 in wild birds or poultry. Since the fifth farm, like the relationship between the first and second, had no linkage to the other farms, it is likely that the infections are due to wild birds carrying high path H5N2.

Although high path H5N2 has never been reported in wild birds in Canada, it has been reported in wild birds in China and the H5 has been the Fujian lineage (clade 2.3.4), raising concerns that the H5N2 in Fraser Valley is this Asian strain.

Distinguishing Asian H5 from North American H5 is done by comparing sequences, which can be done in seconds, and by now Winnipeg undoubtedly has enough sequence data to make that determination, but they have been alarmingly silent.

If this H5N2 was North American, Winnipeg would have offered assurances that the lineage in Fraser Valley is similar to the low path that has been responsible for prior outbreaks.

The silence from Winnipeg is deafening, and raises serious concerns that the H5N2 in Fraser Valley is Asian in origin.

The CFIA National Centre for Foreign Animal Diseases (NCFAD) has now isolated a Notifiable Avian Influenza Virus (AIV) from the index farm. The AIV isolate was confirmed as H5N2. The closest match in Genbank for the N gene is A/American green-winged teal/California/HKWF406/2007(H5N2), accession number: CY033446. The closest match in Genbank for the H gene is A/American green-winged teal/California/HKWF609/2007(H5N2), accession number: CY033444, as reported in the immediate notification. Based on gene sequencing results, the virus was determined to be of low virulence. The NCFAD will now proceed with the determination of the IVPI index. Note by the OIE Animal Health Information Department: H5 and H7 avian influenza in its low pathogenic form in poultry is a notifiable disease as per Chapter 10.4. on avian influenza of the Terrestrial Animal Health Code (2008).

Avian Dis. 2014 Mar;58(1):1-7.Characterization of a low pathogenic avian influenza H5N2 virus isolated from a turkey breeder flock in Manitoba, Canada.Berhane Y, Joseph T, Kehler H, Hisanaga T, Embury-Hyatt C, Diederich S, McGreevy KH, Handel K, Cottam-Birt C, Pasick J.AbstractIn November 2010, an outbreak of avian influenza (AI) due to the H5N2 subtype virus occurred in a turkey breeder farm in northern Manitoba, Canada. The only clinical signs observed were depression, decrease in food consumption, and loss of egg production. The hemagglutinin (HA) cleavage (HA(0)) site of the isolated H5N2 virus was PQRETR/GLF, consistent with low pathogenic AI viruses. The intravenous pathogenicity index of this virus was zero. Whole-genome sequencing of two isolates that originated from two different barns was performed, and both isolates had 100% identical protein sequence in PB2, HA, NP, M1, M2, NS1, and NS2. The remaining gene segments (PB1, PA, and NA) had a single amino-acid difference when compared with each other. The nucleotide and protein sequences of eight gene segments from both isolates showed 99 or greater identity with other AI viruses that have been circulating in free-living aquatic birds in Canada and the United States within the last 10 yr. Phylogenetic analysis of the HA and neuraminidase (NA) gene segments showed that these viruses are closely related to other H5 strains that have been isolated from Manitoba and other parts of Canada. Serologic testing of archived serum samples collected from these turkeys a week before the outbreak showed no evidence of AI infection. In addition, other farms that were located within 3 km radius from the infected farm and farms that had epidemiologic connection with the farm also tested negative for the presence of H5N2 AI virus or antibody. This indicates that the virus might have been introduced to the farm from wild aquatic birds only a short time before detection. Results of this study highlight the importance of early detection and the significance of ongoing Canada-wide surveillance of AI in domestic poultry as well as in wild aquatic birds/ducks.

Avian Dis. 2014 Mar;58(1):1-7.Characterization of a low pathogenic avian influenza H5N2 virus isolated from a turkey breeder flock in Manitoba, Canada.Berhane Y, Joseph T, Kehler H, Hisanaga T, Embury-Hyatt C, Diederich S, McGreevy KH, Handel K, Cottam-Birt C, Pasick J.AbstractIn November 2010, an outbreak of avian influenza (AI) due to the H5N2 subtype virus occurred in a turkey breeder farm in northern Manitoba, Canada. The only clinical signs observed were depression, decrease in food consumption, and loss of egg production. The hemagglutinin (HA) cleavage (HA(0)) site of the isolated H5N2 virus was PQRETR/GLF, consistent with low pathogenic AI viruses. The intravenous pathogenicity index of this virus was zero. Whole-genome sequencing of two isolates that originated from two different barns was performed, and both isolates had 100% identical protein sequence in PB2, HA, NP, M1, M2, NS1, and NS2. The remaining gene segments (PB1, PA, and NA) had a single amino-acid difference when compared with each other. The nucleotide and protein sequences of eight gene segments from both isolates showed 99 or greater identity with other AI viruses that have been circulating in free-living aquatic birds in Canada and the United States within the last 10 yr. Phylogenetic analysis of the HA and neuraminidase (NA) gene segments showed that these viruses are closely related to other H5 strains that have been isolated from Manitoba and other parts of Canada. Serologic testing of archived serum samples collected from these turkeys a week before the outbreak showed no evidence of AI infection. In addition, other farms that were located within 3 km radius from the infected farm and farms that had epidemiologic connection with the farm also tested negative for the presence of H5N2 AI virus or antibody. This indicates that the virus might have been introduced to the farm from wild aquatic birds only a short time before detection. Results of this study highlight the importance of early detection and the significance of ongoing Canada-wide surveillance of AI in domestic poultry as well as in wild aquatic birds/ducks.

This is the first outbreak of Notifiable Avian Influenza (NAI) detected in the province of Manitoba. The farm has been quarantined by the Canadian Food Inspection Agency (CFIA) and investigation will be conducted in compliance with the Canada's Notifiable Avian Influenza Hazard Specific Plan. A stamping out policy will be applied. Preliminary results from the National Center for Foreign Animal Diseases in Winnipeg indicate the presence of a H5N2 subtype avian influenza virus (PCR). Sequence analysis of the PCR products indicates that the cleavage site is consistent with low pathogenic avian influenza virus H5. Closest matches (99% identity) in Genbank are to North American H5N2 viruses from wild birds. Virus isolation is underway and additional testing is to come, including the intravenous pathogenicity index test. NAI surveillance has been in place in domestic poultry in Canada for many years and this outbreak is limited to the province of Manitoba. Note by the OIE Animal Health Information Department: H5 and H7 avian influenza in its low pathogenic form in poultry is a notifiable disease as per Chapter 10.4. on avian influenza of the Terrestrial Animal Health Code (2010).

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